Final answer:
The line indicating Celia has night-gloves made of Tripsy's hide along with puppy water suggests she belongs to a higher social class due to the ownership of non-essential luxury items.
Step-by-step explanation:
The line from Jonathan Swift's poem The Lady's Dressing Room that would best help the reader infer Celia's social class is A. There Night-gloves made of Tripsy's Hide, / Bequeath'd by Tripsy when she died, / With Puppy Water. This line suggests that Celia has access to fine, possibly luxurious materials and pet-related accessories, which, along with the mention of bequeathing, often form parts of the upper class's lifestyle. Items such as night-gloves and puppy water indicate that Celia is well-off enough to own non-essential, cosmetic, or luxury items, shedding light on her higher social status.